The background of the invention will be discussed in two parts:
1. Field of the Invention
This invention relates to ball bumpers for a ball rolling game and more particularly to a ball bumper for a pinball machine.
2. Description of the Prior Art
In pinball machine playing apparatus, a metal ball traverses an inclined playing surface, the metal ball being projected from a start position by a manually-operated spring-biased shooter to travel up an incline guideway to return down the playing surface under the force of gravity. Various switches, "post" bumpers, and "slingshot" bumpers are positioned about the playing surface to be impacted along the path of travel of the ball. Adjacent the bottom of the incline, and sometimes at intermediate points, are flipper mechanisms which are solenoid actuated and operator controlled to redirect the ball up the inclined playing surface upon command and under control of the operator. Other guiding elements and barriers are often interposed on the playing surface to increase the amount of skill required for the game. In conjunction with the various switches and obstacles, electrical circuitry is employed to convert the impact of the playing ball at various points into scoring, which is normally visually displayed on the face of the vertical compartment at the end of the pinball machine opposite the operator's position.
The slingshot mechanism hereinabove referred to is a ball bumper assembly which may comprise two, three or more posts extending generally perpendicular to the playing surface and about which is suspended a resilient elastic band disposed generally parallel to the playing surface, the band being adapted for contact by the approximate mid-point of the playing ball. In some such slingshot assemblies, a leaf switch is disposed immediately behind and spaced from the elastic band, the switch being contacted by the band upon impact of the ball to actuate other devices such as scoring means, with the redirection of the ball being effected by the resilient force of the elastic band. In other slingshot assemblies, a solenoid actuated "kicker" arm is disposed immediately behind and spaced from the elastic band with a pair of leaf switches disposed on either side thereof for contact by the elastic band upon impact of a rolling ball, the closing of the leaf switches energizing the solenoid to actuate the kicker arm against the elastic band to thereby redirect the rolling ball with additional impetus.
Some ball bumpers which have been previously devised, of the "post" type are shown in U.S. Pat. No. 2,209,589 which is a combination ball switch and bumper wherein spaced parallel contact plates encircle the posts with the weight of the metal ball urging the flexible top plate into contact with the lower plate to thereby complete an electrical circuit; 2,727,743 which is a post bumper with a movable skirt; and 2,501,021 in which the post has a conical surface encircled by a coil spring member which is urged outwardly upon downward axial movement of the conical surface to re-project the ball.
Many of such posts employ switch means in contact therewith to effect scoring or actuation of other electrical parts.
In some pinball machine type devices, all or a portion of the playing field has been rendered conductive to utilize the metal ball as part of an electrical circuit which is completed when the metal ball impacts with another conductive member to thereby complete an electrical circuit. In U.S. Pat. No. 2,191,209; 2,219,898; and 2,184,866 the playing field is a metal plate with various posts, projections or bumpers being engaged by the ball to complete electrical circuits for actuating solenoids or scoring apparatus. In U.S. Pat. No. 3,348,844 the game effects scoring by means of the ball bridging the gaps of electrically conductive strips embedded in the playing surface.
In many of the above-referenced patents, where the devices employ the ball as a means of bridging electrodes or conductive members to actuate a solenoid, the impact of the ball in closing the circuit is momentary in form and often times, the solenoid traverses only a small amount of movement due to the momentary actuation, thereby effectively diminishing the impact or thrust of the solenoid in redirecting the ball.
Accordingly, it is an object of this invention to provide a new and improved ball bumper assembly.
It is another object of this invention to provide a new and improved slingshot ball bumper assembly.
It is still another object of this invention to provide a new and improved ball bumper assembly having electrical circuit means for actuating a solenoid to pivot a kicker arm to redirect the ball.